With the development of electronic technology, various electronic devices have been developed. In recent years, in accordance with the miniaturization of electronic devices, portable electronic devices such as mobile phones and table PCs have been widely used.
Wearable portable electronic devices such as smart watches and smart glasses have been developed in recent years. Such electronic devices may provide various functions as interoperating with other electronic devices such as mobile phones, tablet PCs, and TVs.
The above-mentioned portable electronic devices use batteries as power in general due to their portable property. When a battery is discharged, a portable electronic device becomes unavailable without charging or replacing the battery. Accordingly, a user cannot use an electronic device when it is needed due to battery discharge.